/**
# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
**/

package containerd

import (
	"fmt"

	"github.com/NVIDIA/nvidia-container-toolkit/pkg/config/engine"
	"github.com/NVIDIA/nvidia-container-toolkit/pkg/config/toml"
)

// AddRuntime adds a runtime to the containerd config
func (c *Config) AddRuntime(name string, path string, setAsDefault bool) error {
	if c == nil || c.Tree == nil {
		return fmt.Errorf("config is nil")
	}
	defaultRuntimeOptions := c.GetDefaultRuntimeOptions()
	return c.AddRuntimeWithOptions(name, path, setAsDefault, defaultRuntimeOptions)
}

func (c *Config) GetDefaultRuntimeOptions() interface{} {
	runtimeNamesForConfig := engine.GetLowLevelRuntimes(c)
	for _, r := range runtimeNamesForConfig {
		options := c.GetSubtreeByPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", r})
		if options != nil {
			c.Logger.Debugf("Using options from runtime %v: %v", r, options)
			return options.Copy()
		}
	}
	c.Logger.Warningf("Could not infer options from runtimes %v", runtimeNamesForConfig)
	options, _ := toml.TreeFromMap(map[string]interface{}{
		"runtime_type":                    c.RuntimeType,
		"runtime_root":                    "",
		"runtime_engine":                  "",
		"privileged_without_host_devices": false,
	})
	return options
}

func (c *Config) AddRuntimeWithOptions(name string, path string, setAsDefault bool, options interface{}) error {
	config := *c.Tree

	config.Set("version", c.Version)

	if options != nil {
		config.SetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", name}, options)
	}
	if len(c.ContainerAnnotations) > 0 {
		annotations, err := c.getStringArrayValue([]string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", name, "container_annotations"})
		if err != nil {
			return err
		}
		annotations = append(c.ContainerAnnotations, annotations...)
		config.SetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", name, "container_annotations"}, annotations)
	}

	config.SetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", name, "options", "BinaryName"}, path)

	if setAsDefault {
		config.SetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"}, name)
	} else {
		defaultRuntime, ok := config.GetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"}).(string)
		if ok && defaultRuntime == name {
			config.DeletePath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"})
		}
	}
	*c.Tree = config
	return nil
}

func (c *Config) getStringArrayValue(path []string) ([]string, error) {
	if c == nil || c.Tree == nil {
		return nil, nil
	}

	config := *c.Tree
	if !config.HasPath(path) {
		return nil, nil
	}
	annotationsI, ok := config.GetPath(path).([]interface{})
	if !ok {
		return nil, fmt.Errorf("invalid annotations: %v", annotationsI)
	}

	var annotations []string
	for _, annotation := range annotationsI {
		a, ok := annotation.(string)
		if !ok {
			return nil, fmt.Errorf("invalid annotation: %v", annotation)
		}
		annotations = append(annotations, a)
	}

	return annotations, nil
}

// DefaultRuntime returns the default runtime for the containerd config.
func (c Config) DefaultRuntime() string {
	if runtime, ok := c.GetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"}).(string); ok {
		return runtime
	}
	return ""
}

// EnableCDI sets the enable_cdi field in the Containerd config to true.
func (c *Config) EnableCDI() {
	config := *c.Tree
	config.SetPath([]string{"plugins", c.CRIRuntimePluginName, "enable_cdi"}, true)
	*c.Tree = config
}

// RemoveRuntime removes a runtime from the containerd config.
func (c *Config) RemoveRuntime(name string) error {
	if c == nil || c.Tree == nil {
		return nil
	}

	config := *c.Tree

	config.DeletePath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", name})
	if runtime, ok := config.GetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"}).(string); ok {
		if runtime == name {
			config.DeletePath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"})
		}
	}

	runtimePath := []string{"plugins", c.CRIRuntimePluginName, "containerd", "runtimes", name}
	for i := 0; i < len(runtimePath); i++ {
		if runtimes, ok := config.GetPath(runtimePath[:len(runtimePath)-i]).(*toml.Tree); ok {
			if len(runtimes.Keys()) == 0 {
				config.DeletePath(runtimePath[:len(runtimePath)-i])
			}
		}
	}

	if len(config.Keys()) == 1 && config.Keys()[0] == "version" {
		config.Delete("version")
	}

	*c.Tree = config
	return nil
}

// UpdateDefaultRuntime updates the default runtime setting in the config.
// When action is 'set' the provided runtime name is set as the default.
// When action is 'unset' we make sure the provided runtime name is not
// the default.
func (c *Config) UpdateDefaultRuntime(name string, action string) error {
	if action != engine.UpdateActionSet && action != engine.UpdateActionUnset {
		return fmt.Errorf("invalid action %q, valid actions are %q and %q", action, engine.UpdateActionSet, engine.UpdateActionUnset)
	}

	if c == nil || c.Tree == nil {
		if action == engine.UpdateActionSet {
			return fmt.Errorf("config toml is nil")
		}
		return nil
	}

	config := *c.Tree
	if action == engine.UpdateActionSet {
		config.SetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"}, name)
	} else {
		defaultRuntime, ok := config.GetPath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"}).(string)
		if ok && defaultRuntime == name {
			config.DeletePath([]string{"plugins", c.CRIRuntimePluginName, "containerd", "default_runtime_name"})
		}
	}

	*c.Tree = config
	return nil
}
